Well my post has been censored but it doesn't matter. I say it again (perhaps more politely) David Axe knows little about spaceflight and it is more clickbait than anything else. As for the Daily Mail it is hardly better.

I think we are talking at cross purposes here as I was referring to the classified report that Aviation Week were reporting on.

I reacted to this post, more exactly to the links, which are pretty bad (a nuclear space bomber ? really ? powered by fairy dust ?)

Yet Another SCramjet powered plan.

It just does not add up.

The Russians have an ICBM that can hit anywhere on the planet in less than 30 mins already. They've sunk a lot of cash into that and it seems to work alright.

As has been noted an X37b could carry a nuclear warhead in it's payload bay but why would it?

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"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11 Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly. STS-Keeping most of the stakeholders happy most of the time.

Sounds to me more like a call for more money by someone frustrated at the current lack of progress..

After all, it wouldn't be the first time in the history of aerospace that "The Russians Are Coming!" evoked a response from those holding the purse-strings.

Yeah like that time people complained about Sputnik just for money......

Or maybe there is a real threat that unbiased experts now recognize as a threat, after all it is very arrogant to doubt the advanced engineering and determination of both Russia and China to develop hypersonic weapons.

Or maybe there is a real threat that unbiased experts now recognize as a threat, after all it is very arrogant to doubt the advanced engineering and determination of both Russia and China to develop hypersonic weapons.

Historically the US has flown ramjet missiles to M5. It just took a stuck fuel valve and IIRC worked quite well (till it ran out of fuel)

The problem with hypersonic flight is not that it can't be done, it's when people insist on doing it in the atmosphere and using a SCramjet to do it. If you're OK with using a rocket it's (relatively speaking) not that difficult. If you want longer range in the same package then ramjets can already do that with reasonable T/W.

Engineering a long range hypersonic missile using a conventional ramjet is within the current SoA. The toughest part is likely to be the structure and the TPS.

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"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11 Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly. STS-Keeping most of the stakeholders happy most of the time.

However, Weiss hints that work on a combined cycle propulsion system and other key advances needed for a viable hypersonic vehicle are reaching readiness levels sufficient for incorporation into some form of demonstrator. Following critical ground demonstrator tests from 2013 through 2017, Lockheed Martin is believed to be on track to begin development of an optionally piloted flight research vehicle (FRV) starting as early as next year. The FRV is expected to be around the same size as an F-22 and powered by a full-scale, combined cycle engine.

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“The combined cycle work is still occurring and obviously a big breakthrough in the air-breathing side of hypersonics is the propulsion system,” Weiss adds. “So this is not just on combined cycle but on other elements of propulsion system.”The technology of the “air breather has been matured and work is continuing on those capabilities to demonstrate that they are ready to go and be fielded,” he adds.

I'd thought even a demonstrator testing at hypersonic velocities in the big empty of Area 51 is going to be noticeable?

The tests were conducted under the auspices of the Hypersonic International Flight Research Experimentation (HiFIRE) programme, says Australia's Department of Defence in a statement.

In the statement, defence minister Marise Payne congratulated Canberra's Defence Science and Technology Group (DST) and the US Air Force Research Laboratory (AFRL) "on another successful hypersonic flight at Woomera test range."

She said that the tests have achieved "significant milestones, including design assembly, and pre-flight testing of the hypersonic vehicles and design of complex avionics and control systems."

She said Canberra and Washington DC are drafting plans for future hypersonic work.

The statement also thanked Boeing, BAE Systems, and the University of Queensland as partners on the programme.

I'd thought even a demonstrator testing at hypersonic velocities in the big empty of Area 51 is going to be noticeable?

Maybe, but taken in concert with your post above, if the tests were held at Woomera, there's no-one anywhere close enough to see, hear or care..

« Last Edit: 07/13/2017 12:11 AM by CameronD »

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With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they aregoing to land, and it could be dangerous sitting under them as they fly overhead.

I do find it amusing that the UQ article starts by saying "Commercialised flight faster than five times the speed of sound has been brought one step closer.." but then links to the above video of the launch with DoD end credits... Heh.

« Last Edit: 07/17/2017 05:51 AM by CameronD »

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With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they aregoing to land, and it could be dangerous sitting under them as they fly overhead.

One of the troubles with hypersonic systems is people don't compare like with like.

Experimental SCramjets seem to have about a T/W ratio of about 2 or 3:1.

The J58 engine and nacelle package on the SR71 was around 2.5:1 (and you really need that nacelle to make the whole concept work).

But 1) That package could fly the aircraft from a standing standing start on the runway. 2) The aircraft leaked a lot until it had warmed up enough for the plates to seal (as did Concorde BTW). It was not an issue because JP7 did not burn without substantial effort.3) JP7 required a separate logistics supply chain to deliver it, including dedicated tanker aircraft. 3) ConOps for the SR71 was to takeoff mostly empty and require air to air refueling for most fuel loading. This lowered the fire hazard but also would have lowered the landing gear strength requirements significantly.

All of which was acceptable in the Cold War for the unique capabilities it gave the US at the time.

JP 7 has been out of production for decades and was several times more expensive than conventional fuel.

SCramjets can't accelerate a plane from a standing start, and given the 80+ years people have worked on ramjets they probably never will.

That ConOps won't work with aircraft carriers. It's never been made to work with any civilian aircraft and if you require the aircraft to run on a fuel that's not liquid at room temperature (LH2 or Methane) that's a complete non starter.

I strongly doubt the "SR72" is anywhere close to being built, despite what LM will no doubt say.

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"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11 Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly. STS-Keeping most of the stakeholders happy most of the time.

One of the troubles with hypersonic systems is people don't compare like with like.

Experimental SCramjets seem to have about a T/W ratio of about 2 or 3:1.

The J58 engine and nacelle package on the SR71 was around 2.5:1 (and you really need that nacelle to make the whole concept work).

But 1) That package could fly the aircraft from a standing standing start on the runway. 2) The aircraft leaked a lot until it had warmed up enough for the plates to seal (as did Concorde BTW). It was not an issue because JP7 did not burn without substantial effort.3) JP7 required a separate logistics supply chain to deliver it, including dedicated tanker aircraft. 3) ConOps for the SR71 was to takeoff mostly empty and require air to air refueling for most fuel loading. This lowered the fire hazard but also would have lowered the landing gear strength requirements significantly.

All of which was acceptable in the Cold War for the unique capabilities it gave the US at the time.

JP 7 has been out of production for decades and was several times more expensive than conventional fuel.

SCramjets can't accelerate a plane from a standing start, and given the 80+ years people have worked on ramjets they probably never will.

That ConOps won't work with aircraft carriers. It's never been made to work with any civilian aircraft and if you require the aircraft to run on a fuel that's not liquid at room temperature (LH2 or Methane) that's a complete non starter.

I strongly doubt the "SR72" is anywhere close to being built, despite what LM will no doubt say.

As it's a highly classified program for the most part starting what is or isn't possible within it is a fools errand.

All this post does is seemingly point out your pre-existing prejudices on the topic.

As it's a highly classified program for the most part starting what is or isn't possible within it is a fools errand.

It's a non existent programme.

LM's PR offensive has been to get it to get their Powerpoint funded.

The days when the CIA could build (literally) a squadron of very large M3+ planes in a few years in near complete secrecy are over.

I think the fact that every SCramjet that has ever been flight tested has flown on a rocket (despite at least 6 decades of research and several $Bn spent on the concept) first says a great deal about the viability of the idea.

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"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11 Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly. STS-Keeping most of the stakeholders happy most of the time.

....Tucker’s optimism is based on a dramatic upswing in the Air Force hypersonic research budget. Compared to 2012, when the Air Force spent just under $79 million on hypersonic science and technology programs, the service requested more than $292 million for the same areas in the 2018 presidential budget. Of this, $90 million was requested for prototyping.

While a number of classified hypersonic missile efforts are thought to be underway in the U.S., the only acknowledged committed government research developments are a series of technology demonstrator programs led by DARPA. These include two high-speed strike weapons: the Tactical Boost Glide (TBG) program and the Hypersonic Air-Breathing Weapon (HAWC). The TBG is a follow-on to the unsuccessful HTV-2 hypersonic cruise vehicle demonstrator and is a rocket-launched hypersonic weapon capable of flying more than 1,000 mi. in 10 min. The TBG, in development by Lockheed Martin, is attempting to repackage the high lift-to-drag aerodynamic and aerothermal design concepts of the global-range HTV-2 into a smaller, tactical-range weapon

Raytheon Missile Systems and Lockheed Martin are meanwhile competing for the HAWC, a follow-on to the Air Force Research Laboratory’s (AFRL) successful Boeing X-51A WaveRider hypersonic scramjet engine demonstrator.

Leveraging elements of these DARPA/AFRL efforts, the Air Force has meanwhile begun efforts to develop an air-launched Hypersonic Conventional Strike Weapon. Boeing, Lockheed Martin, Northrop Grumman, Raytheon Missile Systems and Orbital ATK have all been listed as potential developers of the precision strike missile, which the service says will be fired at “high-value, time-critical fixed and relocatable surface targets.” A contract for development of the weapon—which will be conventionally armed, powered by solid rocket and guided by an integrated GPS/INS (inertial guidance system)—will be awarded in early 2018.

Beyond missiles and XS-1, DARPA’s other major hypersonic program is the Advanced Full-Range Engine (AFRE), a ground demonstrator of a turbine-based combined-cycle engine that will enable an aircraft to operate at Mach 5+ from standard runways. Launched 18 months ago, AFRE is a “full-scale engine, and will validate [that] we can have an effective engine,” says DARPA Tactical Technology Office Director Brad Tousley. “We need the same sort of thing as the J58 was in the SR-71, and AFRE is the same sort of thing. If that is successful, we think it would open up the trade space for us to work together with the Air Force, the U.S. Navy and others on a really ‘no-kidding’ reusable hypersonic aircraft......

A TBCC system combines a turbine engine for low-speed operations with a dualmode ramjet (DMRJ) for high-speed operations via a common inlet and nozzle servingboth the low-speed and high-speed flowpaths."

and

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DARPA is only interested in proposals addressing full system solutions for AFRE.

DARPA is not interested in lower Mach solutions such as a turbo-ramjet orsolutions that use accelerants.

So basically it's a SCRamjet or nothing,despite the fact Ramjets have been demonstrated to operate to Mach 5 already.

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TBCC Maturation activities (Water Injection with an F405-RR-402 Turbine Engine andthe Low Mach DMRJ Free-Jet) as they become available

F405-RR-402 - Upgrade of F405-RR-401, incorporating Mk 951 technology, certified 2008. Did not enter into service due to funding issues.

Which means it is a non after-burning low BP turbofan of 6500 lbf thrust, redesigned for longer service life and a new FADEC.

This looks like a USN engine upgrade programme that did not get funded, so the engine is a one off, although no doubt more could be made.

That sketches in a single engine drone (AFAIK all the aircraft that use it are twin engined). The US consultancy that looked at a SABRE based TSTO for the USAF reckoned you need aengine thrust = 50% of GTOW to go supersonic so that gives a GTOW of about 13 000 lb

I don't really see why they don't just hand the money to Aerojet. It's basically written so they are the only people who can win this.

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"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11 Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly. STS-Keeping most of the stakeholders happy most of the time.

That said most people would think that after 6 decades and about $4Bn the USG might have a better idea. Note that expenditure.

It's not that SCRamjets have had no funding. It's that they have had a huge amount of cash put in over decades and they still haven't delivered anything close to an engine, let alone a vehicle to carry it.

Quote from: Star One

I think we'd already established you don't like scramjets so there's nothing new here.

I'm sorry your mind is so closed that that is all you could read into my post. I posted it here because, y'know its about "general hypersonic" stuff.

And because this actually looks like the power plant for the fabled SR72.

I will be very impressed to see a full scale ground test of an engine across 5 Mach numbers, since SABRE was developed to avoid precisely that requirement, given how difficult it is (I'd love to find out what Arnold spent on the APTU upgrade).

I will be even more impressed if they manage to put it into a vehicle that weighs less than 13 000lb for $65m.

To put this in perspective what I have trouble with is the absolute insistence that a ramjet cannot do the job, despite the fact that the J58 and its nacelle could get 70% of the way to M5 before the first SCramjet contract was signed at the APL.

It's not the goal I object to.

It's the absolute, fanatical, dogmatic insistence that only an SCramjet can do this, when the actual operating range of conventional ramjets has still not been established.

[EDIT it's especially odd when you see (from the BAA) that they don't require start up of the DMRJ below M2.5. Given that ramjets of the 1950's could cruise at M2 this is not especially low. Indeed 3 Mach numbers puts it at M5.5 without any SC requirement. M2 startup would put it comfortably within the state of practice for high performance military aircraft, without the following features.

Running a far more conventional turbofan up to M3 was viewed as quite viable, with pre compressor cooling, 40 years ago. The SCramjet would have to give phenomenal improvements in fuel consumption, along with operating without exotic fuel grades like JP7, to justify it's inclusion in a design. ]

That's why people have called them "scamjets" in the past.

« Last Edit: 08/12/2017 02:39 PM by john smith 19 »

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"Solids are a branch of fireworks, not rocketry. :-) :-) ", Henry Spencer 1/28/11 Averse to bold? You must be in marketing."It's all in the sequencing" K. Mattingly. STS-Keeping most of the stakeholders happy most of the time.

I realize that the SR-71 and YF-12 were short of the true definition of hypersonic(IIRC Hypersonic relates to Mach 5 and above).If the Mach 3+ SR-71/YF-12 were still operational, would NASA have enough demand for testing at over Mach 3 to keep at least a pair of them airworthy?